Process for producing pure sulphur from crude materials containing sulphur in an uninterrupted operation



Nov. 28, 1933. K. VON SZOMBATHY ,9 6,959

PROCESS FOR PRODUCING PURE SULPHUR FROM CRUDE MATERIALS CONTAINING SULPHUR IN AN UNINTERRUPTED OPERATION Filed June 26, 1930 .2241 Meat/2 0?" kojaman/ l/dn, \f zamzazf/i Patented Nov. 28, 1933 FROM.CRUDE MATERIALS-CONTAINING" v v TERRUPTED OPER SULPHUR IN AN.

IQN;

" iKolo'manvon 'Szombathy, 'Dortmund," Germany ,ippuafion June 26.1920, sir-a No. 464,005. l i and in Switzerland 8,1929 g p 4' c1aims.f(c1. -2s-226)' The proposal has frequentlybeenput forwardu to use thionates for absorbing sulphuretted hy-* drogen or sulphur dioxide gas by preferablye'm-.

ploying thiosulphates for absorbing'sulphuretted hydrogen. In studying polythionicacids and their salts it was. ascertained that the higher polythionic acids and polythionates, e. g., tetrathionic acid, show a sulphur-adding action. In this manner it is possible to produce higher su.- 'phur compounds from lower 'polythionates. The higher polythionates, the pentathionates and hexathionates slowly liberate the sulphur taken up, thus being reduced to tetrathionates." It

has been found thatthis separation of the sul- "phur takes place in the form of precipitated sulphur. However, if provision is made' for the presence of collodial sulphuror sulphur in. the

nascent state in the solution during the-separa-" tion of the sulphur, this is readily taken up again repeatedly given=off in theformof precipitated sulphur. According to the invention; "the sulphur content of the crude material is-converted in the usual manner'into sulphuretted hydrogen "and sulphur dioxide gases, the gases obtained (being at the same time led into a preferably. finely distributed concentrated solution of higher polythionatessoluble in water, such as alkali or earth alkali salts of. pentathionic or hexathionic acids, and the liberated sulphur separated from the salt solution and dried, while the salt solution freed from the precipitated-sulphur is constantly returned to the reaction vessel for the further production of sulphur. At the same time, however, the solution takes up the sulphur in the nascent state which is formed by the action of the sulphuretted hydrogen on the sulphurous acid, the tetrathionate being thus regenerated to again form penta-hexathionates. This process may be accelerated by adding small quantities of alcohols, for instance,,1-2 per cent. of glycerine, to the polythionate solution, and further by maintaining the temperature of the fiuid, ,to

Whilst the gases are being added, the separation of the sulphur and the regeneration of the solution are effected very rapidly. In otherrespects the reaction is very tardy. However. if

the addition of sulphuretted hydrogen isin exby tetrathionates and in favorable circumstances least adapted'for continuous service. lf ther'e That is an excessof sulphurous acid comparedQWith;

the proportion stated, collodial sulphur is chiefly} produced which gradually agglonierates"the sulphur already extracted'and precipitated. I'nthlis' 5 4.1 Y conditionit is a diflicultmatter to wash the finished sulphurl Naturally,.minor fluctuations 0fc'- curring during the admission of the gases'do no" v harm as'any variationmay readi1y-be'detected';7..

and compensated for. 7 Y I W While the hitherto. known processes were chiefly basedion the fact that thesulphurous' acid m is, on i the'gjone hand, absorbed by .thiosulphate, whereby'trithionate and tetrathionate are formed from J thiosulphate, and, on "the other hand, 5111;, phuretted hydrogen was employed' fo'r reducing: a

the aforementioned polythionates, only-*tetra-f thionates and-pehtathionates or hexathionatesf" should be-presentin the same p'roportion'in the v sulphate'is never present in said solution}: Should" polythionate soliition of the new process. Thicthe're'be an excessof tetrathionate orpentathio hate, it is a sign that thejgasesf were not cor' fi rectly added.

From the foregoingit will, therefordbe' evident that'in this case it is not a matter, of" gas ab- .sorption, but that it ratherconcerns. a purely chemical process. carried out in the wet state in which the sulphur is separated catalytically from the employed pentathionate solution, and

the possibility is, given ofproducing. considerable quantities of the solution in a short time.

As the separation of the sulphurand the I simultaneous assimilation of the sulphur'areuniformly elfected by thepolythionates, the proportionv betweenv the various polythionates remains constant, and the solution possesses a constantly unchanged activity if the addition of the,

gasesis correctly carriedthrough, 'Incase. a pentathionate solution exists, it isonly necessary to provide for an uninterrupted supply of'sulloo phuretted hydrogen and sulphur dioxide in the: correctproportion, and for a separation ofthe freed precipitated sulphur from. the solution by means of a filtering device, and for thesolution' freed f rom sulphur being returned to the-cycle of the operation. Hence,the separation of the j J I From the foregoing it will be evident that the yield of sulphur depends solely upon the concentration of the gases. When operating with concentrated gases, a stronger pentathionate solution is preferably used. If, on the otherhand, the gases arediluted, a diluted pentathionate solution will suffice; It has been found that a 10 per cent. pentathionate solution may still be used to advantage. degree appears to lie almost at the lowest limit at which the operation pays; 1 y V The process is chiefly adapted for producing large quantities of sulphur :rmm different crude substances with sulphur content, or also" from crude sulphur; Consequently, only crude materials capable of being easilygasified, such as sulphur ores, pyrites, sulphide cram, copper pyrites, sulphide of lead, crude "sulphur, gas? purifying masses,- etc. comechiefiy under, conadaptedfor carrying out the process as the tem- I into the .pentathionate solution in the mixed or separated stat-e. The main thing is that the. supply is,eifectedsimultaneously and in the correct .iproportion.

sideration.

1 5 Potassium salts'are adapted more than any other salts for preparing apentathionate solution; .Ammonium salt (sal ammoniac) is least perature is constantly maintained at 60 degrees and'higher as long as, the process lasts, and greaterlosses would have to, be reckoned with after some time-on account of the moisture of 'theammon-ium salt.

\Regardingthe supply of gas, it is quite immaterial whether the two gases are conducted The accompanying diagrammatic drawing of a; plant forcarry-ing out the process embodying the invention, and the following description-of a practical application oi-the process,. will sufiice I to makejthesequence of operationsclear with out, any further theoretical explanations being necessary. w s

A potassium-pentathionate solution of 30-32 degrees B. i-sprepared in that equal Volumes of However, dilution to such. a

ately separated and passes through the pipe 8 liquor of the separatedsulphur, the-liquor being thro gh the pipe 2 into the absorbers 5-'7 where it is nely sprayed. Into this finely distributed pentathionate solution sulphuretted hydrogen and sulphur dioxide are introduced through the gas pipes '3' and 4. Owing to the reactionheat, the solution becomes heated to about degrees cent, and this temperature is maintained at a constant level. Whilst the gas is being admitted, the fine, precipitated sulphur is immediinto the filtering device 9' where the separated 10 through the piped)". The filtrate product is forcedback again into the container 1 through the pipes 11, 12"and whereby preferably a collecting vessel l st-with the pipes 15 and 16, or a steaming vessel 17 with the pipes 18 'and 19 may be interposed. The vessel 17 is also in-' tended to serve as a collector for the washing then run off through the drain pipe 20, What I claim is:' Q c 1" 1. The process for producing ,pure'i sulphur from crude rnaterialcontaining sulphur, ,in a

continuous operation, which comprises produc-' ing hydrogen sulphide and sulphur'tdioxide from the crude material, and conducting said sulphide-1 and dioxide simultaneously; into. a polythionates solution as a Washing fluid, the hydrogensulphide ular equivalent with respect, tothe' amount 'of' sulphur dioxide in-order t'oobtain a stated hydro: gen sulphide tension. in anwabsorber, and the solution being maintained at a temperature. of 1111 between 45-65 C. in a continuous closed cycle. 2. A process according to claim '1, in-which the' polythionate solution contains a small amount'of alcohol. T1

33. A process according to claim 1, in which the polythionate solution contains a. small amount of glycerine. r I r:

4. A process according to claim 1, in which at least twice asmuch hydrogensulphide'as sulphur I dioxide is utilized at altemperaturel: between 120.

15L6 5 C. in the'closed' cycle.

I KOLOMAN vofi szoMBATHY.

'105 a being introduced inexcess of more than a inolec-. 

